Revascularization of a Thrombosed, Previously StentedAorto-Renal Graft Using Combined Directional

Atherectomy and AngioJet Thrombectomy

Ashok Seth, * MD, FRCP, FSCAI, FACC, Atul Mathur, MD, DM, Praveen Chandra, MD, DM,Praveer Aggarwal, MD, DM, and Narendra Khanna, MD, DM

We report an interesting case with bilateral PTFE aorto-renal grafts of which one graftunderwent balloon angioplasty and stenting for proximal stenosis. Combined debulkingby AngioJet thrombectomy and Simpsons directional atherectomy was performed withinthe stent following reocclusion of the graft 9 months later. Cathet. Cardiovasc. Intervent.46:85–88, 1999. r 1999 Wiley-Liss, Inc.

Key words: atherectomy; thrombectomy; graft

INTRODUCTION

Renovascular hypertension is the most common formof secondary hypertension that can be successfully treatedby both surgical revascularization and percutaneous bal-loon angioplasty with stenting [1–4]. Aorto-renal bypassgrafting of occluded renal arteries has been performedwith good initial success and long-term patency rates[2,3]. We report an interesting case in which bilateralaorto-renal grafting was performed in a young male withrenovascular hypertension. Fifteen years later one graftoccluded requiring balloon dilatation and stent implanta-tion. The same graft thrombosed 9 months later andunderwent combined debulking using an AngioJet throm-bectomy catheter and directional atherectomy, leading tocomplete revascularization.

CASE REPORT

A 24-year-old male with severe refractory hyperten-sion (maximum blood pressure of 240/160 mm Hg) hadsignificant bilateral renal artery stenosis secondary tofibromuscular dysplasia. He received bilateral aorto-renalpolytetrafluoroethylene (PTFE) grafts with dramatic re-sponse in blood pressure control. An angiogram done 5years after surgery revealed fully patent grafts. Heremained normotensive for 10 more years without receiv-ing any medication. Isotope renal scans and abdominalDoppler ultrasound done on two separate occasions werenormal.

The blood pressure became persistently elevated 15years following surgery, mandating reinstitution of acombination of calcium channel and a beta blocker drugs.

Angiogram revealed a severe stenosis in the proximalpart of the right aorto-renal graft, which was treated withballoon dilatation and deployment of a 7 mm3 23 mmWallstent (Schneider) due to significant elastic recoil.This resulted in a reduction in drugs required for bloodpressure control. Aspirin was not given due to coexistentG6PD deficiency. The patient was discharged on warfarinand ticlopidine, which he continued for 8 months, afterwhich ticlopidine was discontinued. Within 15 days ofthis he presented with accelerated hypertension and acuteright flank pain. An isotope renogram revealed a nonex-creting right kidney and angiography revealed totalocclusion of the graft proximally within the previouslydeployed stent (Fig. 1). A descending aortogram showedthe native renal arteries occluded flush with the aortaprecluding any further interventions on these vessels.

An urgent thrombectomy was performed via the leftfemoral route using an 8 Fr multipurpose guiding cath-eter. The lesion was crossed using an intermediate 0.014’’wire and initially dilated using a 2.5 mm3 20 mmballoon catheter all along the length of the graft. Exten-sive thrombus occluding the graft (Fig. 2) was debulked,making four passes with the AngioJet LF140 thrombec-tomy catheter (Possis Medical) and a good blood flowwas restored with marked decrease in thrombus burden.The patient experienced severe pain in the right flank

Department of Cardiology, Escorts Heart Institute and ResearchCenter, New Delhi, India.

*Correspondence to: Dr. Ashok Seth, Chief of Department of Interven-tional Cardiology, Escorts Heart Institute and Research Center, OkhlaRoad, New Delhi 110025, India. E-mail: atul_mathur@hotmail.com

Received 20 January 1998; Revision accepted 19 July 1998

Catheterization and Cardiovascular Interventions 46:85–88 (1999)

r 1999 Wiley-Liss, Inc.

each time a pass was made with the thrombectomycatheter. A residual well-organized thrombus in theproximal part of the graft within the stent (Fig. 3) couldnot be broken down with a 3.5 mm3 20 mm noncompli-ant balloon at high pressures. This was then debulkedwith directional atherectomy, making eight cuts with a 7French Simpsons atherocath (Fig. 4). Another mass ofresidual thrombus in the distal end of the graft wellbeyond the stent was also debulked with directionalatherectomy, making three more cuts. Low pressure (4atm) balloon inflations were subsequently performed inthe graft using a 6.03 20 mm Bypass Speedy balloon.The histological analysis of the tissue samples obtainedrevealed laminated scaffolds of fibrin with a paucity ofcellular components. The final angiogram showed excel-lent flow without any significant residual stenosis in thegraft (Fig. 5) and no evidence of distal embolization in theintrarenal circulation.

The blood pressure gradually decreased over the next24 hr and the antihypertensive medication could bedowngraded. The patient was discharged on low-molecular-weight heparin for 10 days followed by oralanticoagulation. Ticlopidine 250 mg was advised twicedaily. An abdominal Doppler ultrasound done a weeklater showed widely patent graft with good flow.

DISCUSSION

Surgical revascularization for occlusive renal arterydisease results in good long-term functional as well asanatomical results [2]. Since fibromuscular occlusiverenal disease frequently affects the younger population,these patients are more likely to outlive the patency of thegrafts. The PTFE aorto-renal grafts for bilateral renalartery stenosis used in this patient functioned well for 15years before the development of stenosis, which wassuccessfully treated with balloon angioplasty and stent-ing. Despite adequate anticoagulant and antiplatlet therapy,

Fig. 1. Totally occluded PTFE aorto-renal graft with a shortstump seen within the proximally placed stent.

Fig. 2. Restoration of flow following initial balloon dilatation,which outlines extensive thrombus, occluding the graft.

86 Seth et al.

there was recurrence of fibrin deposition within theproximal part of the stent, which subsequently gotorganized. This was evident from the residual obstructionafter removal of soft fresh thrombus with the AngioJetthrombectomy catheter. Although angioscopy was notperformed in this case, it is presumed that stents im-planted in such grafts are unlikely to endothelialize andthe bare surface of such devices would provide a scaffoldfor thrombus formation even after several months. Theacute thrombotic occlusion over the underlying organizedfibrin thrombus in the stent occurred within 2 weeks ofdiscontinuing antiplatlet therapy and subsequently led tothe whole graft being filled with thrombus. The debulkingof the graft was performed to salvage the kidney from theacute ischemic insult. Although aggressive combinedantiplatlets and anticoagulation have been advised follow-ing this procedure, this patient will electively undergorepeated surgical revascularization.

The severe flank pain experienced by the patient duringeach pass with the AngioJet catheter in the PTFE graft isvery unusual. This can be hypothesized to be due todisruptive pressure waves emanating from this device.These waves when transmitted to the renal capsule resultin the pain sensation.

Thrombectomy with AngioJet catheter and directionalatherectomy using the Simpsons atherocath has beensuccessfully performed on native coronary arteries, by-pass grafts as well as peripheral vessels [5–8]. However,there is no experience with these devices in PTFE grafts.Furthermore, directional atherectomy for removal oforganized thrombus within a stented PTFE graft has alsonot been reported so far. Hence this is an unusual casewhere both AngioJet thrombectomy and directional ather-ectomy have been performed to debulk an occludedPTFE aorto-renal graft to remove both fresh and orga-nized thrombus. Both these devices have been usedwithin and beyond the stented segment without anyadverse effects.

Fig. 3. Residual organized thrombus within the stent (brokenarrow) and beyond the stent (arrow) following thrombectomyusing the AngioJet catheter.

Fig. 4. Debulking within the stent using Simpsons atherocath.

Aorto-Renal Graft Revascularization 87

CONCLUSIONS

Revascularization of occluded PTFE aorto-renal graftscan be performed percutaneously using both balloon

angioplasty and the newer debulking devices. However,deployment of stents within these grafts does not ensurelong-term patency and requires intensive combined anti-platlet and antithrombotic therapy.

REFERENCES

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8. Vorwerk D, Sohn M, Schurmann K, Hoogeveen Y, Gladziwa U,Gunther RW. Hydrodynamic thrombectomy of hemodialysis fistu-las: First clinical results. J Vasc Intervent Radiol 1994;5:813–821.Department of Cardiology, Escorts Heart Institute and ResearchCenter, New Delhi, India

Fig. 5. Final result showing no residual narrowing.

88 Seth et al.